Determining temperature ratings for children's cold weather clothing

This study examined the physical and physiological differences between children and adults that affect body heat generation and losses and then developed a heat loss model for determining the temperature ratings of cold weather clothing designed for use by children of various ages. The thermal insulation values of selected jackets were measured using a heated manikin dressed in two base ensembles, and the temperature ratings were calculated using the model. The results indicated that the type of garments used in the base ensemble had a major effect on jacket ensemble insulation and the predicted comfort temperature. For a given level of insulation, the temperature rating decreased as the wearer's age and activity level increased. This is probably because children have a higher surface area per unit mass ratio than adults, and they lose heat faster. However, this effect is partially offset by their higher metabolic rates.     

Air-sources,supply and cooling

Abstract

A general overview is presented of the alternative methods of supplying air to conditioned garments. Both compressed air and low-pressure, high-volume air systems are described and many of the aspects involved in the design of the system are discussed, e.g. the types of compressor and fan available, the air-volume requirement, the system pressure drop, pipe sizing and the actual system installation with the particular problems that can arise.

The relationship between the air volume and the supply temperature is discussed and a comparison is made between the alternative systems available for air cooling.

The vortex tube is described together with the air turbine and comparison is made with conventional vapour-compression equipment. These systems are compared to high-volume systems which could provide large quantities of ambient air at low pressure and cost.     

The relation between clothing thickness and cooling during motorcycling

The relation between clothing thickness and the cooling rate of a single motorcyclist has been determined at air temperatures between — 1°C and 24°C. The importance of a windproof oversuit and helmet liner have been studied. The effect of a fairing on the motorcycle has been measured. Much thicker and more windproof clothing than is generally available is needed to maintain normal body temperature on an unfaired motorcycle in winter: a mean clothing thickness of 20 mm inside a windproof oversuit is needed at 5°C, but is only effective if sweat does not accumulate inside the clothing.     

A test battery related to ergonomics of protective clothing

Specialised protective clothing, such as that worn by firefighters, is usually tested only to standards which give requirements for the materials used (e.g. EN469). However, this testing often neglects the effect the manufacturing process of the garment has on the material properties, the effects of clothing design, sizing and fit, as well as the interaction of the clothing with other components of the standard gear for the profession. Such effects can only be tested by looking at the protective gear as a whole. This paper deals with methods to do additional testing on protective garments with firefighter clothing as example. In other words, methods which go beyond EN469. Human subject tests for physiological load, heat protection, ergonomic design, loss of performance, rain/moisture protection and conspicuity/visibility of the clothing are described and proposed for evaluation of protective clothing in general and for further development of standards on firefighters' clothing.     

Perceptions of temperature,moisture and comfort in clothing during environmental transients

A study has been carried out to investigate the psychophysical mechanisms of the perception of temperature and moisture sensations in clothing during environmental transients. A series of wear trials was conducted to measure the psychological perception of thermal and moisture sensations and the simultaneous temperature and humidity at the skin surface, fabric surface and in the clothing under simulated moderate rain conditions. Jumpers made from wool and acrylic fibres were used in the trial. Analysis has been carried out to study the relationship between psychological perceptions of temperature and moisture and the objectively measured skin and fabric temperatures and relative humidity in clothing microclimate. The perception of warmth seems to follow Fechner's law and Stevens' power law, having positive relationships with the skin temperature and fabric temperatures. The perception of dampness appears to follow Fechner's law more closely than Stevens' power law with a negative relationship with skin temperature, and is nonlinearly and positively correlated with relative humidity in clothing microclimate. The perception of comfort is positively related to the perception of warmth and negatively to the perception of dampness. This perception of comfort is positively related to the skin temperature, which appears to follow both Fechner's law and Stevens' law, also non-linearly and negatively related to relative humidity in clothing microclimate.     

A CAD system for multi-style thermal functional design of clothing

Designing clothing with good thermal functional performance is very demanding and time-consuming if we follow traditional design methods. An innovative method consisting of a CAD system, allowing the designer to perform multi-style clothing thermal functional design on a customized virtual human body, is presented in this paper. The new functionalities of the virtual system provide the abilities to perform intelligent design of different clothing styles and materials for different body parts according to individual design requirements, namely design of various categories of clothing, such as hat, coat, trousers, gloves and shoes in the same design scheme. The designed clothing can be worn on a virtual human body and set in various wearing scenarios. The thermal behaviors in the human body-clothing-environment are simulated to predict the thermal performance of clothing and thermal response of the human body at multi-parts. 2D/3D visualization and animation of the simulation results are presented to help the designers to preview and determine whether the thermal performance of clothing is satisfactory and then obtain feedback to improve their designs iteratively.     

Combined effects of fabric air permeability and moisture absorption on clothing microclimate and subjective sensation during intermittent exercise at 27 degrees C

The present paper aimed at determining the combined effects of two different levels of air permeability and moisture absorption, in terms of clothing microclimate and subjective sensation, in resting and exercising subjects at an ambient temperature of 27 °C, a relative humidity of 50% and an air velocity of 0.14 m s^-1. Three kinds of clothing ensemble were investigated: (1) polyester clothing with low moisture absorption and low air permeability (A), (2) polyester clothing with low moisture absorption and high air permeability (B), and (3) cotton clothing with high moisture absorption and high air permeability (C). The subjects exercised for 10 min on a cycle ergometer at an intensity of 30% maximal oxygen uptake and then had a 10 min rest. This sequence was repeated four times. The main findings are summarized as follows: (1) The clothing microclimate humidity in the back area was significantly higher in A than in B, and in C than in B. (2) The clothing microclimate temperature in the chest area was significantly higher in B than in A, and in B than in C. (3) The clothing microclimate temperature in the back area was significantly higher in C than in B. (4) The clothing surface temperature was significantly higher in C than in B. (5) Although the positive relationships between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at chest for the same sweat rate was lower in C than in A and B. (6) Although the positive relationships between subjective sensation and forearm sweat rates were significantly confirmed in all three kinds of clothing, the subjective discomfort seemed to be reduced more effectively in C than in A and B for the same sweat rate. These results were discussed in terms of thermal physiology and combined effects of air permeability and moisture absorbency of the fabrics.     

A multi-disciplinary strategy for computer-aided clothing thermal engineering design

The designers and manufactures in apparel industry have urgent needs in designing clothing with superior thermal functions with user-friendly and cost-effective design tools. This paper presents a multi-disciplinary strategy for computer-aided clothing thermal engineering design. It provides a systematical approach to integrate multi-disciplinary knowledge and transfer it into engineering-oriented design tools, thus the designers and manufacturers can easily carry out 1D, 2D and even 3D clothing thermal engineering designs according to the practical design requirements with a short design cycle and low design cost. The research work of this strategy begins from the investigation of the role of the thermal functions of clothing in the thermal comfort of human body. Then the framework is proposed to integrate the multi-disciplinary knowledge and illustrate the process to achieve the thermal engineering design of clothing. The important issues in the realization of computational simulation are addressed, including multi-scale model integration, data availability of characteristic parameters and hierarchical computational scheme. To issue easy-to-use design tools, the thermal functional design of clothing is quantified with important influence parameters, and the user-friendly wizard is designed for the CAD system development. Finally, the design applications of this strategy are discussed in terms of 1D, 2D and 3D thermal engineering designs with versatile CAD systems.     

Accredited standards committee for information processing systems, X3

This article described the activities and structure of the Accredited Standards Committee X3 - Information Processing Systems, operating under the procedures of ANSI. The author, a member of both X3 and IEEE, has been extensively involved in the X3 standardization process, and describes X3 from the perspective of an organization devoted to developing voluntary standards for the information processing industry, using the dual concepts of consensus and due process to guide their work.     

Problems and strategies for software component testing standards

What does it mean to say that an item of software has been tested? Unfortunately, currently accepted standards are inadequate to give the confidence the user needs and the meaningful objective for the supplier. This paper assesses the currently available standards, mainly in the component testing area and advocates that the British Computer Society proto-standard should be taken as a basis for a formal standard. The paper is intended for those concerned with software quality.     

A fuzzy neural network model for predicting clothing thermal comfort

This paper presents a Fuzzy Neural Network (FNN) based local to overall thermal sensation model for prediction of clothing thermal function in functional textile design system. Unlike previous experimental and regression analysis approaches, this model depends on direct factors of human thermal response — body core and skin temperatures. First the local sensation is predicted by a FNN network using local body part skin temperatures, their change rates, and core temperature as inputs; then the overall sensation is predicted. This is also performed by a FNN network. The FNN networks are developed on the basis of the Feed-Forward Back-Propagation (FFBP) network; the advantage of using fuzzy logic here is to reduce the requirement of training data. The simulation result shows a good correlation between predicted and the traditional experimental data.     

3D quantification of microclimate volume in layered clothing for the prediction of clothing insulation

Garment fit and resultant air volume is a crucial factor in thermal insulation, and yet, it has been difficult to quantify the air volume of clothing microclimate and relate it to the thermal insulation value just using the information on the size of clothing pattern without actual 3D volume measurement in wear condition. As earlier methods for the computation of air volume in clothing microclimate, vacuum over suit and circumference model have been used. However, these methods have inevitable disadvantages in terms of cost or accuracy due to the limitations of measurement equipment. In this paper, the phase-shifting moiré topography was introduced as one of the 3D scanning tools to measure the air volume of clothing microclimate quantitatively. The purpose of this research is to adopt a non-contact image scanning technology, phase-shifting moiré topography, to ascertain relationship between air volume and insulation value of layered clothing systems in wear situations where the 2D fabric creates new conditions in 3D spaces. The insulation of vests over shirts as a layered clothing system was measured with a thermal manikin in the environmental condition of 20 degrees C, 65% RH and air velocity of 0.79 m/s. As the pattern size increased, the insulation of the clothing system was increased. But beyond a certain limit, the insulation started to decrease due to convection and ventilation, which is more apparent when only the vest was worn over the torso of manikin. The relationship between clothing air volume and insulation was difficult to predict with a single vest due to the extreme openings which induced active ventilation. But when the vest was worn over the shirt, the effects of thickness of the fabrics on insulation were less pronounced compared with that of air volume. In conclusion, phase-shifting moiré topography was one of the efficient and accurate ways of quantifying air volume and its distribution across the clothing microclimate. It is also noted that air volume becomes more crucial factor in predicting thermal insulation when clothing is layered.     

The development of an intelligent system for customized clothing making

This study presents the development of an intelligent system for customized clothing making. The system involves body dimension collection, clothing pattern generation and fabric cutting. First, body dimensions can be collected by analyzing the 3D scanning images or 2D photographs. Further, the clothing patterns can be generated by using computer-aided design (CAD) techniques based on the collected dimensions. By presenting the generated clothing patterns in DXF (Drawing Exchange Format), the CNC laser-cutting machine can then cut the fabric into pattern pieces automatically. Finally, by integrating the system with the processes of garment sewing, fitting test and final adjustment, the concept of customized clothing making can be realized. It can not only assure good fitness of the customized clothing but also reduce human efforts, costs, and production time.     

The accuracy of estimating the thermal insulation of clothing ensembles - the effect of appraisers

The effect of the appraisers on the estimation of the thermal insulation of clothing ensembles was investigated. Nine appraisers, four experienced and five inexperienced, estimated the total thermal insulation by summing the values for individual garments. Lists of individual garments worn by workers were given during thermal comfort measurements carried out in shops and stores during one winter and summer. The beginners estimated the thermal insulation as accurately as the experienced appraisers. There were, however, great individual differences, for which three main reasons were found. Interpolation between the insulation provided by two garments was insufficient, and the insulation of these garments should be checked in more precise tables. Classification of the garments into heavy, medium and light clothing items was not adequate, and garments not listed by the workers confused the estimation given by different appraisers. The effect of error in thermal insulation on the PMV index is negligible if more than one appraiser estimates the thermal insulation and the mean of the estimates is used.     

An overview of standards and guidelines for visual display terminals

This paper provides a discussion of several standards and guidelines for design of visual display terminal (VDT) workplaces. The material represents products of government agencies, commercial standards organisations and of labour unions. Seven documents are reviewed: US MIL STD 1472-C, German DIN 66234, British HSE, Swedish ISO Proposal, British APEX, US NYCOSH, and Australian ACTU-VTHC. There is considerable disagreement in the specification of design parameters in these standards. The issues are discussed in terms of their importance and the availability of supporting ergonomics research. There are several types of VDT tasks and the number and variety of applications are growing rapidly. Due to these factors and the development of new display technologies, different recommendations may be appropriate depending upon the task and the technology. Research and careful deliberation will be required to deal with this development.     

Design of a flexible, integrated testing system for STEP and OMG standards

New software standards supporting integration of manufacturing and engineering systems are emerging at a rapid pace. Two groups, the Object Management Group (OMG) and the community producing the Standard for the Exchange of Product Model Data (STEP, formally known as ISO 10303), dominate in the production of standards for manufacturing and engineering industries. Their standards are based on common methods, which can be exploited in developing tests for systems supporting the standards. This paper describes the methods employed and a system that builds on those methods to support the automatic and rapid development of conformance tests for the emerging standards.